6WN HighlightsWeek Ending Saturday, April 25.Listeners who remember the delightful series of recitals presented on the National programme by the noted South American cantatrice, Olga Praguer Coelho. will enjoy Rio Nights, in which special records made by this artist for the ABC are featured. The programme is a glimpse ot Rio de la-niero and its night life, and features In addition Nino .Martini, La Argentina and the LeCUOna South American Dance Band. It is programmed on Sunday at 7.15. The CTA Choir will appear at 9 15. Another in the series Australia at War will be broadcast at 9.4 0.